A number of applications exist for the stimulation of electrically-excitable tissue. One prominent application is functional electrical stimulation (FES), by which electrical excitation is utilized to cause muscle contraction. FES can be implemented with either implanted electrodes or from skin surface electrodes. The control of muscle contraction from skin surface electrodes can be referred to as surface FES. Such control can be used to restore movement to individuals with paralysis (e.g., from spinal cord injury), or to facilitate muscle contraction in individuals with other neuromuscular impairments or injury. FES has been utilized over the past few decades to provide physiological and/or therapeutic benefits to individuals with neuromuscular impairments, and its use is currently considered a standard of care in the clinical community concerned with neuromuscular impairment. FES can be used to enable or facilitate activities such as walking, which can be referred to as FES-aided gait. In such activities, it is necessary to stimulate several muscle groups and control the output of each group independently of the other groups. For example, some combination of hip flexor, hip extensor, knee flexor, and knee extensor muscle groups must be independently controlled in order to generate walking patterns.